De ascentiis



Feb. 21, 1956 G. DE ASCENTIIS Filed 061;. 4, 1954 DRAFT CONTROL FOR FURNACES INVEN TOR.

ATTORNEY United States Patent DRAFT CONTROL FOR FURNACES Gaetano De Ascentiis, Camden, N. J. Application ()ctober 4, 1954, Serial No. 464M351 7 Claims. (C l. 110-19163) This invention relates to heating equipment for buildings, and more particularly to draft controls for furnaces, stoves, heaters and the like all of which are referred to simply as furnaces hereinafter.

One of the difficulties encountered in most furnace installations is the lack of adequate heat conservation, with attendant loss of ethciency. In many cases, no, or at best very ineffective, provision is made for preventingcool air from passing through the tire box of the furnace during idle. periods. Neither is provision made for preventing backdraft or downdraft in the chimney. from passing down into the furnace. The former increases. the heat loss, while the latter may blow out the flame and even force gases which are combustion products through the furnace and into the room. Both conditions clearly result in reducing operating elficiency and may even create obnoxious conditions.

The prunary object of my invention is to provide an improved draft control for furnaces which will avoid the aforementioned difiiculties.

More particularly, it is an object of my invention to provide an improved draft control for furnaces which will conserve heat and will increase the operating efficiency of furnaces.

Another object of my invention is to provide an improved draft control for furnaces which will prevent appreciable passage of cold air through the furnace fire box during idle periods of the furnace.

Still another object of my invention is to provide an improved draft control for furnaces which will prevent downdraft or backdraft in the chimney from reaching the furnace, whereby the possibility of blowing out the flame from this cause is eliminated.

A further object of my invention is to provide an improved draft control which will prevent obnoxious gases resulting from combustion of the fuel from passing out to the room because of backdraft.

Still another object of my invention is to provide an improved draft control as aforesaid which can be applied easily to existing furnace installations.

It is also an object of my invention to provide an improved draft control which is simple in construction, easy to install, entirely automatic in operation, and highly efficient in use.

The invention, both as to its organization and method of operation, as well as additional objects and advantages thereof, will be better understood from the following description, when read in connection with the accompanying drawing in which:

Figure 1 is a perspective view, partly in section, of a furnace installation embodying one form of draft control according to my invention,

Figure 2 is a fragmentary side elevation, tion, of the stove pipe of Figure 1 which connects the furnace to the chimney and in which the draft control mechanism is mounted, the damper of such mechanism being shown closed, and

partly in sec- Patented Feb. 21,

Figure 3 is a view similar to Figure 2 but showing. the damper open.

Referring more particularly to the drawing, wherein the same' reference numerals designate similar parts throughout, there are shown a furnace 1 and a chimney therefor 3 connected by a smoke pipe 5 'made up of one. or more sections of stove pipe 7, 7a, The furnace 1 may be part of a forced draft system, as where an oil burne'r is employed. If desired, a laterally-extending barometric draft control 9. of any known form, such as a Draft-A- Stat, for example, may be connected to the smoke pipe 5 near the chimney, as to the pipe section 7a.

I have found that conventional draft. controls ofv the. type indicated are inadequate to properly control the draft in the pipe 5 to conserve heat'most efliciently. In accordance with my invention, I provide in'the pipe section 7 a damper ll'which is pivotally mounted therein by means of a pair of diametrically opposedpivot pins 131 To one of the pins 13, there is secured an arm 15. on which a weight 17 is slidably mounted. The weight 17 normally maintains the damper 11in its closed position, as shown in Figs. 1 and 2. The damper 11 isof such shape and size that, in its said closed position, it fills the cross sectional area of the pipe 7 at the point where the damper isv located therein. By adjusting the weight 17 along the arm 15 and locking it in a desired position by means of a'set screw 19, the force of 'adraft' from the furnace required to open the damper 11 to'its open p0fsi tion shown in Figure 3 can be determined.

Also mounted in the pipe section '7 on the side thereof leading from the damper 11 to the furnace 1 is a baffle 21 which has. a bend 23. therein to provide two angularly related bafiie portions 21a and 21b. The baffle 21 may be secured to the pipe section 7 in any suitable manner, as by means of a bracket 25. The portion 21a of the baflle is preferably, but not necessarily, disposed substantially along the axis of the pipe section 7 and either in a plane which also includes the pivotal axis 13-13 of the damper or in a plane which is substantially parallel to and slightly displaced from the first mentioned plane. The second portion 21b of the baflie 21 is thus disposed at an angle to the axis of the pipe section '7, being inclined downwardly away from the furnace 1 as illustrated and covering approximately half the cross sectional area of the pipe section 7. The end 210 of the baflle portion 21a, which is the one nearest to the damper 11, is slightly spaced from the damper, as best seen in Fig. 2. Above the battle portion 21a and also its own pivotal axis 1313, the damper 11 may be provided with one or more openings 27, if desired, or the damper may be made of a perforated plate to allow combustion gases to pass on to the chimney from the furnace even if the damper 11 is closed. This prevents such gases from building up great pressure and prevents warping of the damper.

Normally, the damper 1.1 is maintained closed by the weight 17. The weight is placed in such a position on the arm 15 that a slight amount of pressure on the furnace side of the damper will open the damper. Thus, when the oil burner goes on, the blower thereof will provide flow pressure to cause the damper to open and remain open during operation of the burner. In coal fired furnaces using blowers, the same result will be produced. The inclined portion 21b of the bafile 21 directs flow of combustion gas to the damper, as shown by the arrows A in Figs. 1 and 3, to insure opening of the damper and passage of such gases to the chimney. When the burner shuts off, the flow pressure in a forward direction (i. e., furnace to chimney) ceases and the damper 11 returns to its closed position. The damper 11 and the baflle 21 to reflect back to the furnace heat rays represented by the arrows B in Fig. 2. Thus, the heat is 3. greatly conserved. At the same time, the closed damper 11 and the baffle 21 also cooperate to prevent cold air from passing up through the furnace firebox during idle periods of the burner, thereby avoiding needless cooling of the furnace and thus further preventing waste of heat. Moreover, should a downdraft or backdraft occur in the chimney, such draft will assist the Weight 17 in maintaining the damper 11 closed, if it is already closed, and will itself, if of sufiicient force to be harmful, close the damper if it happens to be Open.

From the foregoing description, it will be apparent to those skilled in the art that I have provided an improved and effective draft control for furnaces which functions to increase operating efficiency of the furnace and effects savings in fuel cost. It will also be apparent that my improved draft control can be readily applied to existing installations by merely replacing a section of conventional stove pipe with one provided with such draft control. Although I have shown and described but one embodiment of my invention, it will also be apparent that other forms thereof are possible. I therefore desire that the foregoing shall be taken merely as illustrative and not as limitmg.

I claim as my invention:

1. A draft control for furnaces comprising a section of pipe adapted to form a portion of a smoke pipe connect ing a furnace to its chimney and having a first end for connection to the furnace and a second end for connection to the chimney, a pivoted damper in said section, means normally maintaining said damper closed, said means being yieldable in response to a draft from said pipe section first end to permit such draft to open said damper, and bafiie means in said pipe section between said first end thereof and said damper disposed adjacent to said damper, said baffle means having a first portion disposed substantially along the axis of said pipe section 4 and a second portion disposed in angular relation to said first portion and facing said pipe section first end whereby to guide toward said pipe section second end products of combustion when said damper is open and to cooperate with said damper to reflect back to said pipe section first end heat rays coming from the furnace when said damper is closed.

2. A draft control according to claim 1 wherein said second bafile portion is located nearest to said first end of said pipe section.

3. A draft control according to claim 1 wherein said first bafile portion is substantially in a plane which includes the pivotal axis of said damper.

4. A draft control according to claim 3 wherein the end of said first baffle portion nearest to said damper is spaced slightly from said damper.

5. A draft control according to claim 4 wherein said damper is provided with an opening in the portion thereof which is on the same side of said plane as is said second baffle portion.

6. A draft control according to claim 1 wherein said damper has at least one opening therein.

7. A draft control according to claim 1 wherein said damper is of a size and shape to fill the cross sectional area of said pipe section at the point of its location and when said damper is in closed position, the pivotal mounting of said damper being such that a backdraft along said pipe section tends to assist said first named means in maintaining said damper closed.

References Cited in the file of this patent UNITED STATES PATENTS 1,358,854 Kendall Nov. 16, 1920 1,641,875 Beaulieu Sept. 6, 1927 1,672,758 Given June 5, 1928 2,557,210 Viola June 19, 1951 

